Such a system is known from U.S. Pat. No. 5,581,484, incorporated herein by reference. The known system has a finger-mounted input device for manually entering information into a computer. The device uses a pressure sensor and a pair of acceleration sensors removably attached to the finger tip of a user. The pressure sensor senses a pressure when the finger presses against an object, e.g., a table surface. The acceleration sensors measure the acceleration of the finger. The sensors are mounted in a flexible glove. The signals of the sensors are relayed to a computer that calculates the relative position of the finger. Twice integrating an acceleration measured gives a coordinate of the current position of the finger relative to a begin position. The pressure sensor is used to validate the signal of the acceleration sensors. The known system allows a user to enter data into the system as if he or she were typing on a physical keyboard, such as the standard QWERTY keyboard.